The invention relates to a cordless finger sensor for measuring blood oxygen saturation. More particularly, the present invention provides a module that fits into a special recess within an oximeter so that when in use, it becomes an integral part of the instrument. The invention allows for removal and replacement of the sensing module in case of component failure. Elimination of the sensor cable makes for easier carrying and storage of the device.
A small cordless oximeter in which all of the electronics are contained within the finger-gripping means is described in U.S. Pat. No. 5,490,523 to Isaacson et al. This device eliminates the external cord of a conventional oximeter and securely holds the patient's finger without support from the operator. Its external spring and lack of an internal pivot point prevent it from being used inside other devices. The design of the Isaacson oximeter also prevents the average user from replacing the sensor components in case of failure. In the event of LED or photodetector malfunction, the entire device is usually replaced.
A pulse oximeter with both replaceable and reusable components is taught by Swedlow et al in U.S. Pat. No. 5,209,250. Their device uses a conventional cord to connect the sensor to an oximeter. The replaceable part, containing only the LEDs, is wrapped over the end of the finger. The sensor has laterally extending adhesive webs which are then folded around the finger to hold the sensor in place.
Tobler et al in U.S. Pat. No. 5,645,440 describe a novel connector for oximeter sensors. This invention, assigned to Masimo, allows the user to quickly discard a disposable sensor at the end of a conventional cable and replace it with another one.
The sensor to be described eliminates the need for a separate finger sensor with its attendant cable. The sensor allows the insertion of any adult finger and that of children down to the age of about three. During use it is an integral part of the surrounding oximeter but can be readily removed and replaced by the user in the event of failure of the LEDs or photodetector. Its design enables it to be used with a variety of instruments from small saturation-only devices to larger multi-parameter instruments which can also measure temperature, end-tidal CO.sub.2 or blood pressure.
A primary object of the invention is to provide a sensing module with the sensor having its own internal spring for gripping various size fingers, from those of large adults to children as young as three years of age.
A further object of the invention is to provide a sensing module which slides into a recess within an oximeter so that it is an integral part of the oximeter without the need for any external cords or cables.
Another object of the invention is to provide a sensing module which fits within the oximeter recess so securely that no special screws or latches are needed to hold it in place.
A further object of the invention is to provide a sensing module that can be used in many different types of monitoring devices. These can be small saturation-only instruments, devices measuring saturation and temperature, or devices measuring saturation, expired CO.sub.2 or blood pressure.